The invention relates to a linear drive device comprising a linear motor, which has a motor housing with a housing cavity, in which an axially displaceable piston separates two working spaces from each other and which together with a power output rod and a control rod constitutes a common moving drive unit, the two rods being arranged on opposite axial sides of the piston and, extending through the respectively associated housing end plate, which shuts off the housing cavity at the end thereof, extend out of a power output end and a control end of the motor housing, an electrically operated actuating device in the form of a valve device having a solenoid for effecting the supply and/or discharge of pneumatic or hydraulic fluid in relation to at least one working space for actuating the linear motor, and at least one sensor for responding to certain positions of translation of the control rod, the valve device, solenoid and the sensor being arranged adjacent to the control end of the linear motor.
In the case of a linear drive device of this type as for instance described in European patent publication 10 355 179 A, the linear motor is more particularly designed in the form of a piston and cylinder unit, whose piston rod represents the actuating or output rod, which is able to be connected with a component to be moved or with some other part to be acted upon. In this case the control rod together with at least one sensor is responsible for producing control signals on the basis of which the valve arrangement is operated, which is responsible for the distribution of working fluid to the working spaces of the linear motor. A control device is provided for processing the control signals and the operation of the valve arrangement, such control device generally being mounted externally.
This known linear drive device already has the advantage that the main components are joined together as a unit able to be handled as such. However, the space requirement for this device is still excessive for many applications more particularly owning to the valve arrangement and sensors placed to the side of the control rod. Furthermore a flange-mounted holding structure is necessary at one end in order to attach these parts securely and in a manner free of vibration. A further point to be considered is that the assembly of the valve arrangement and of the sensors on the holding structure is slow, because free, exposed working fluid lines and control lines are still necessary.